Feeding efficiency of wolf spider, Pardosa pseudoannulata (Boesenberg and Strand) against Brown Planthopper, Nilaparvata lugens (Stal)

Abstract

Study on functional response of wolf spider, Pardosa pseudoannulata in relation to different prey densities of 3rd and 4th instar brown planthopper (BPH) nymphs was undertaken in glass jar and in microcosm arena. The number of attacked prey (Ha) and prey density per unit area over a period of time (HT) were determined and regression of 1/Ha on 1/HT in microcosm and jar arena revealed functional type II response of wolf spider on BPH nymphs. The attack rate, maximum attack rate and efficiency of attack were high in jar as compared to microcosm experiment but handling time was converse of this. This could be attributed to limited arena of the jar, which reduced searching time of predator and ultimately increased killing rate in jar arena compared to microcosm. The observed feeding tactic of P. pesudoannulata suggested that spiders can have beneficiary role in controlling rice pest such as brown plant hopper in density sensitive way. This functional response of spider provided the good information for understanding the effects of bio control agents in the field.